]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - arch/x86_64/mm/numa.c
[PATCH] x86-64: configurable fake numa node sizes
[linux-2.6-omap-h63xx.git] / arch / x86_64 / mm / numa.c
index 41b8fb069924d9a6b26582688f9421aa44e80d8d..c55936bc6be64cf9dc8854e34edee4e55ca83d65 100644 (file)
@@ -273,125 +273,172 @@ void __init numa_init_array(void)
 
 #ifdef CONFIG_NUMA_EMU
 /* Numa emulation */
-int numa_fake __initdata = 0;
+#define E820_ADDR_HOLE_SIZE(start, end)                                        \
+       (e820_hole_size((start) >> PAGE_SHIFT, (end) >> PAGE_SHIFT) <<  \
+       PAGE_SHIFT)
+char *cmdline __initdata;
 
 /*
- * This function is used to find out if the start and end correspond to
- * different zones.
+ * Setups up nid to range from addr to addr + size.  If the end boundary is
+ * greater than max_addr, then max_addr is used instead.  The return value is 0
+ * if there is additional memory left for allocation past addr and -1 otherwise.
+ * addr is adjusted to be at the end of the node.
  */
-int zone_cross_over(unsigned long start, unsigned long end)
+static int __init setup_node_range(int nid, struct bootnode *nodes, u64 *addr,
+                                  u64 size, u64 max_addr)
 {
-       if ((start < (MAX_DMA32_PFN << PAGE_SHIFT)) &&
-                       (end >= (MAX_DMA32_PFN << PAGE_SHIFT)))
-               return 1;
-       return 0;
+       int ret = 0;
+       nodes[nid].start = *addr;
+       *addr += size;
+       if (*addr >= max_addr) {
+               *addr = max_addr;
+               ret = -1;
+       }
+       nodes[nid].end = *addr;
+       node_set_online(nid);
+       printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
+              nodes[nid].start, nodes[nid].end,
+              (nodes[nid].end - nodes[nid].start) >> 20);
+       return ret;
 }
 
-static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
+/*
+ * Splits num_nodes nodes up equally starting at node_start.  The return value
+ * is the number of nodes split up and addr is adjusted to be at the end of the
+ * last node allocated.
+ */
+static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
+                                     u64 max_addr, int node_start,
+                                     int num_nodes)
 {
-       int i, big;
-       struct bootnode nodes[MAX_NUMNODES];
-       unsigned long sz, old_sz;
-       unsigned long hole_size;
-       unsigned long start, end;
-       unsigned long max_addr = (end_pfn << PAGE_SHIFT);
-
-       start = (start_pfn << PAGE_SHIFT);
-       hole_size = e820_hole_size(start, max_addr);
-       sz = (max_addr - start - hole_size) / numa_fake;
-
-       /* Kludge needed for the hash function */
-
-       old_sz = sz;
-       /*
-        * Round down to the nearest FAKE_NODE_MIN_SIZE.
-        */
-       sz &= FAKE_NODE_MIN_HASH_MASK;
+       unsigned int big;
+       u64 size;
+       int i;
 
+       if (num_nodes <= 0)
+               return -1;
+       if (num_nodes > MAX_NUMNODES)
+               num_nodes = MAX_NUMNODES;
+       size = (max_addr - *addr - E820_ADDR_HOLE_SIZE(*addr, max_addr)) /
+              num_nodes;
        /*
-        * We ensure that each node is at least 64MB big.  Smaller than this
-        * size can cause VM hiccups.
+        * Calculate the number of big nodes that can be allocated as a result
+        * of consolidating the leftovers.
         */
-       if (sz == 0) {
-               printk(KERN_INFO "Not enough memory for %d nodes.  Reducing "
-                               "the number of nodes\n", numa_fake);
-               numa_fake = (max_addr - start - hole_size) / FAKE_NODE_MIN_SIZE;
-               printk(KERN_INFO "Number of fake nodes will be = %d\n",
-                               numa_fake);
-               sz = FAKE_NODE_MIN_SIZE;
+       big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
+             FAKE_NODE_MIN_SIZE;
+
+       /* Round down to nearest FAKE_NODE_MIN_SIZE. */
+       size &= FAKE_NODE_MIN_HASH_MASK;
+       if (!size) {
+               printk(KERN_ERR "Not enough memory for each node.  "
+                      "NUMA emulation disabled.\n");
+               return -1;
        }
-       /*
-        * Find out how many nodes can get an extra NODE_MIN_SIZE granule.
-        * This logic ensures the extra memory gets distributed among as many
-        * nodes as possible (as compared to one single node getting all that
-        * extra memory.
-        */
-       big = ((old_sz - sz) * numa_fake) / FAKE_NODE_MIN_SIZE;
-       printk(KERN_INFO "Fake node Size: %luMB hole_size: %luMB big nodes: "
-                       "%d\n",
-                       (sz >> 20), (hole_size >> 20), big);
-       memset(&nodes,0,sizeof(nodes));
-       end = start;
-       for (i = 0; i < numa_fake; i++) {
-               /*
-                * In case we are not able to allocate enough memory for all
-                * the nodes, we reduce the number of fake nodes.
-                */
-               if (end >= max_addr) {
-                       numa_fake = i - 1;
-                       break;
-               }
-               start = nodes[i].start = end;
-               /*
-                * Final node can have all the remaining memory.
-                */
-               if (i == numa_fake-1)
-                       sz = max_addr - start;
-               end = nodes[i].start + sz;
-               /*
-                * Fir "big" number of nodes get extra granule.
-                */
+
+       for (i = node_start; i < num_nodes + node_start; i++) {
+               u64 end = *addr + size;
                if (i < big)
                        end += FAKE_NODE_MIN_SIZE;
                /*
-                * Iterate over the range to ensure that this node gets at
-                * least sz amount of RAM (excluding holes)
+                * The final node can have the remaining system RAM.  Other
+                * nodes receive roughly the same amount of available pages.
                 */
-               while ((end - start - e820_hole_size(start, end)) < sz) {
-                       end += FAKE_NODE_MIN_SIZE;
-                       if (end >= max_addr)
-                               break;
+               if (i == num_nodes + node_start - 1)
+                       end = max_addr;
+               else
+                       while (end - *addr - E820_ADDR_HOLE_SIZE(*addr, end) <
+                              size) {
+                               end += FAKE_NODE_MIN_SIZE;
+                               if (end > max_addr) {
+                                       end = max_addr;
+                                       break;
+                               }
+                       }
+               if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
+                       break;
+       }
+       return i - node_start + 1;
+}
+
+/*
+ * Sets up the system RAM area from start_pfn to end_pfn according to the
+ * numa=fake command-line option.
+ */
+static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
+{
+       struct bootnode nodes[MAX_NUMNODES];
+       u64 addr = start_pfn << PAGE_SHIFT;
+       u64 max_addr = end_pfn << PAGE_SHIFT;
+       unsigned int coeff;
+       unsigned int num = 0;
+       int num_nodes = 0;
+       u64 size;
+       int i;
+
+       memset(&nodes, 0, sizeof(nodes));
+       /*
+        * If the numa=fake command-line is just a single number N, split the
+        * system RAM into N fake nodes.
+        */
+       if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
+               num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0,
+                                               simple_strtol(cmdline, NULL, 0));
+               if (num_nodes < 0)
+                       return num_nodes;
+               goto out;
+       }
+
+       /* Parse the command line. */
+       for (coeff = 1; ; cmdline++) {
+               if (*cmdline && isdigit(*cmdline)) {
+                       num = num * 10 + *cmdline - '0';
+                       continue;
                }
-               /*
-                * Look at the next node to make sure there is some real memory
-                * to map.  Bad things happen when the only memory present
-                * in a zone on a fake node is IO hole.
-                */
-               while (e820_hole_size(end, end + FAKE_NODE_MIN_SIZE) > 0) {
-                       if (zone_cross_over(start, end + sz)) {
-                               end = (MAX_DMA32_PFN << PAGE_SHIFT);
-                               break;
+               if (*cmdline == '*')
+                       coeff = num;
+               if (!*cmdline || *cmdline == ',') {
+                       /*
+                        * Round down to the nearest FAKE_NODE_MIN_SIZE.
+                        * Command-line coefficients are in megabytes.
+                        */
+                       size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
+                       if (size) {
+                               for (i = 0; i < coeff; i++, num_nodes++)
+                                       if (setup_node_range(num_nodes, nodes,
+                                               &addr, size, max_addr) < 0)
+                                               goto done;
+                               coeff = 1;
                        }
-                       if (end >= max_addr)
-                               break;
-                       end += FAKE_NODE_MIN_SIZE;
                }
-               if (end > max_addr)
-                       end = max_addr;
-               nodes[i].end = end;
-               printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",
-                      i,
-                      nodes[i].start, nodes[i].end,
-                      (nodes[i].end - nodes[i].start) >> 20);
-               node_set_online(i);
-       }
-       memnode_shift = compute_hash_shift(nodes, numa_fake);
-       if (memnode_shift < 0) {
-               memnode_shift = 0;
-               printk(KERN_ERR "No NUMA hash function found. Emulation disabled.\n");
-               return -1;
-       }
-       for_each_online_node(i) {
+               if (!*cmdline)
+                       break;
+               num = 0;
+       }
+done:
+       if (!num_nodes)
+               return -1;
+       /* Fill remainder of system RAM with a final node, if appropriate. */
+       if (addr < max_addr) {
+               setup_node_range(num_nodes, nodes, &addr, max_addr - addr,
+                                max_addr);
+               num_nodes++;
+       }
+out:
+       memnode_shift = compute_hash_shift(nodes, num_nodes);
+       if (memnode_shift < 0) {
+               memnode_shift = 0;
+               printk(KERN_ERR "No NUMA hash function found.  NUMA emulation "
+                      "disabled.\n");
+               return -1;
+       }
+
+       /*
+        * We need to vacate all active ranges that may have been registered by
+        * SRAT.
+        */
+       remove_all_active_ranges();
+       for_each_online_node(i) {
                e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
                                                nodes[i].end >> PAGE_SHIFT);
                setup_node_bootmem(i, nodes[i].start, nodes[i].end);
@@ -399,14 +446,15 @@ static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
        numa_init_array();
        return 0;
 }
-#endif
+#undef E820_ADDR_HOLE_SIZE
+#endif /* CONFIG_NUMA_EMU */
 
 void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
 { 
        int i;
 
 #ifdef CONFIG_NUMA_EMU
-       if (numa_fake && !numa_emulation(start_pfn, end_pfn))
+       if (cmdline && !numa_emulation(start_pfn, end_pfn))
                return;
 #endif
 
@@ -486,11 +534,8 @@ static __init int numa_setup(char *opt)
        if (!strncmp(opt,"off",3))
                numa_off = 1;
 #ifdef CONFIG_NUMA_EMU
-       if(!strncmp(opt, "fake=", 5)) {
-               numa_fake = simple_strtoul(opt+5,NULL,0); ;
-               if (numa_fake >= MAX_NUMNODES)
-                       numa_fake = MAX_NUMNODES;
-       }
+       if (!strncmp(opt, "fake=", 5))
+               cmdline = opt + 5;
 #endif
 #ifdef CONFIG_ACPI_NUMA
        if (!strncmp(opt,"noacpi",6))